The present invention relates to a circuit board for COF (Chip on Film) package, which is capable of preventing an influence of coupling noise on a core block of an integrated circuit. The circuit board may include: a base film defined a core block region overlapping a predetermined location of a core block within an integrated circuit and having the same area as or larger area than the core block; first routing patterns formed on the base film; and a first block pattern covering the core block region. The first routing patterns may be formed outside the first block pattern at the same layer as the first block pattern.